Unable to set up Drupal 10 multisite using subfolders in DDEV (e.g., /site1 and /site2)

First, you may have a better support experience on Slack.

Was the DDEV software documentation helpful or did you have to make the customizations based on your own knowledge of Drupal and nginx?

What does the DDEV configuration file look like?

Is this answer helpful?

Ddev support is currently in discord too.

At a glance it is because the default site exists and the web server hasn't been configured to handle that.

Prepare the Multisite Directory Structure

Create folders for each subsite under web/sites/:

bash

mkdir -p web/sites/site1/files
mkdir -p web/sites/site2/files

cp web/sites/example.settings.php web/sites/site1/settings.php
cp web/sites/example.settings.php web/sites/site2/settings.php

Create Symlinks for Subdirectory Access Important Step

This is the key step that enables subdirectory access:

cd web
# Symlink site paths to index.php
ln -s . site1
ln -s . site2

Note: Use ddev ssh and create symlink using the above command if you are using ddev environment.

Configure sites.php
Create a sites.php file using this command ->
touch web/sites/sites.php
Edit or create web/sites/sites.php:
php

<?php

$sites = [
  'example.ddev.site.site1' => 'site1',
  'example.ddev.site.site2' => 'site2',
];

Drupal converts subdirectory URLs like /site1 into example.ddev.site.site1 internally for multisite resolution.

Configure Database Connections

Edit each site's settings.php to define the correct database.
Example: web/sites/site1/settings.php

$databases['default']['default'] = [
'database' => 'site1',
'username' => 'db',
'password' => 'db',
'host' => 'db',
'port' => 3306,
'driver' => 'mysql',
];

Repeat similarly for site2.

Set File Permissions

chmod -R 775 web/sites/site1/files
chmod -R 775 web/sites/site2/files

Enable .htaccess Rewrite Rules for Subdirectory Sites
Drupal’s default .htaccess is designed for single-site setups. For multisite with subdirectories, we need to ensure Apache knows how to handle requests like /site1/node/1 properly.

Add Rewrite Rules to Top-Level .htaccess
Edit or append to the top of your web/.htaccess:
apache

# Multisite Subdirectory Rewrite Rules


RewriteEngine on

RewriteBase / # Uncomment this line

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteCond %{REQUEST_URI} ^/site1
RewriteRule ^ site1/index.php [L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteCond %{REQUEST_URI} ^/site2
RewriteRule ^ site2/index.php [L]

This ensures:
example.ddev.site/site1/node/1 → routed through site1/index.php (symlinked to ../index.php)

Clean URLs (like /site1/about) resolve properly.

Don't Remove Existing Drupal .htaccess Rules

Run:
ddev/apache restart

Apache will now recognize .htaccess changes.

Install Each Site via Browser

Visit each site in your browser to begin installation:
http://example.ddev.site/site1/core/install.php

http://example.ddev.site/site2/core/install.php

Follow the on-screen prompts to complete installation.

Test the Multisite Setup
After installing:
Go to http://example.ddev.site/site1 — should load Site 1.

Go to http://example.ddev.site/site2 — should load Site 2.

Hope this will help.